Physical Mapping of New High Temperature Adult Plant Resistance (HTAP) Locus in Wheat Cultivar Louise

Wheat is the major source of plant-based food in the world. One of the most severe pathogens that threatens wheat production worldwide is stripe rust caused by Puccinia striiformis f. sp. Tritici. Genetic resistance to rust proved to be the most economically efficient method to control the pathogen. Previously used major resistance genes, while granting strong initial effect, showed rapid loss of function due to pathogen’s evolutionary arms race. Finding durable non-specific resistance is the most current direction for the pathogen control. High temperature adult plant resistance (HTAP) previously reported as promising trait that grants resistance to broad range of stripe rust races with high level of resistance especially in warm climatic conditions. Here we report physical mapping of the novel HTAP locus in wheat cultivar Louise. Louise x Penawawa mapping population was selected for current study based on previous field resistance screenings. Stripe rust inoculation on resistant and susceptible lines was followed by RNA extraction and next generation transcriptome sequencing. Transcriptome analysis with differential expression profiling was used for the selection of putative genes of interest. Further synteny analysis utilizing wheat SNP database followed by target amplifications and restriction essays lead us to the mapping of the polymorphic marker of HTAP locus on the short arm of chromosome 2B.